If he wants more physical revenge, he would do it himself.
If he want to inflict more mental damage, he would order the commoners to do it or give them the choice to do it.
Summon an orc. no that would be too tame, she might enjoy it. summon goblins, naw too stereotypical. use the commoners. that is the key. obviously he isn't going to touch her himself, he has the goddess.
Wondering if he'll make interesting use of the "female" knight in the process of children with the princess, since he mentioned a true form and all. Or I've read too much hentai and thinking too hard about it.
@sshazm
I feel the author is the same as us so the probability of what you said happening is 80%.
I doubt he would do it himself since the reason the hero died is because he rejected the princess, him raping her would make his refusal and death before pointless.
On another note when the princess was stripped the faces of the men in the crowd instantly turn "creep" which is hilarious.
RULE 1. DONT EVRE BETRAY THE HERO!!!!!!
this is the 3rd isekai where they betray the hero after killing the demon king, only to come back for revenge later